The present invention relates to a bubble trap. It has particular application in devices in which the presence of bubbles has a deleterious effect, such devices include, but are not limited to, mechanical ultrasound devices, such as medical ultrasound scanners.
In ultrasonic devices that require an acoustic fluid transmission medium, it is essential that there be no gas bubbles in the path of the acoustic beam. Since some devices have sealed moving drive shafts, leakage through the seal invariably occurs. Consequently, bubbles form in the fluid. Even those devices that do not have dynamic seals can have bubbles due to the permeability of the housing material, typically a plastic. If the internal parts are made of plastic or epoxy, some outgassing within them may also occur, and such outgassing produces gas bubbles. Therefore, it is extremely difficult to keep such devices bubble free, and a convenient means for removing any bubbles present would be a very desirable feature.